An efficient method for the large-scale propagation of Epidendrum secundum using protocorms and leaves from in vitro germination was established. Explants were inoculated in Woody Plant Medium (WPM) supplemented with 6-benzyladenine (BA) (1.0–40.0 µM) for 60 days and cultured in a growth room in darkness (30 days) or with a 16 h photoperiod. Protocorms were most effective for regenerating protocorm-like bodies (PLBs; 100.0%), independent of the presence or absence of light. The leaves were less responsive, and the best results were obtained with the youngest leaves (58.0% PLB induction). BA influenced the responses of protocorms and young leaves, and medium supplemented with 1.0 µM BA was most effective for inducing and regenerating PLBs. The shoots were rooted (100.0%) in WPM without any growth regulator and were transplanted to Isopor trays containing Plantmax florestal® and vermiculite (2:1), with 100.0% survival after 60 days. A histological analysis demonstrated that for both the explants, leaves and protocorms, PLBs were formed from successive divisions of epidermal cells. This simple protocol will be useful for the large-scale propagation of E. secundum.
Key words: Orchidaceae, epiphytic orchid, in vitro propagation, micropropagation.
BA, 6-Benzyladenine; PLBs, protocorm-like bodies; WPM, woody plant medium.